Currently, for an existing liquid crystal grating, especially that used in an autostereoscopic 3D display device, a signal electrode and a common electrode inside it are usually charged bilaterally. FIG. 1 shows one grating substrate of the liquid crystal grating, which includes a base substrate 110, and common electrodes 120 and signal electrodes 130 arranged on the base substrate 110. Two ends of each common electrode 120 are connected to common electrode input lines 141, 142, respectively, so as to charge the common electrode 120. Two ends of each signal electrode 130 are connected to signal electrode input lines 151, 152, respectively, so as to charge the signal electrode 130.
The reason for such a configuration is that the signal electrode input lines 151, 152 and the common electrode input lines 141, 142 in the existing liquid crystal grating are all arranged at a region of a liquid crystal layer, i.e., at a sealant region 180. A ratio of a dielectric coefficient of air to that of liquid crystals is about 1:16, and in order to compensate for a high dielectric coefficient of a liquid crystal environment, it is required to use a metal line as the input line. In addition, in order to ensure the accuracy of signal transmission, it is required to provide the common electrode and the signal electrode with two input lines, respectively, so as to ensure a relatively high transmission frequency. As a result, it is able to charge the signal electrode and the common electrode bilaterally, thereby to ensure good charging effect and driving effect.
Because the common electrode and the signal electrode are provided with two input lines, respectively, the common electrode input lines 141, 142 and the signal electrode input lines 151, 152 need to be arranged at different layers. In addition, between the layers is arranged an insulating layer, in which via-holes are provided. The common electrode input lines 141, 142 are connected to the common electrode 120 through the via-hole 160 while the signal electrode input lines 151, 152 are connected to the signal electrode 130 through the via-hole 170, so as to prevent signal interference therebetween. However, the resultant liquid crystal grating substrate will be relatively thick, and the manufacturing difficulty and the production cost will increase.